def solve_s(s1,s2):
    a=s1[0]+s2[0]*(-(s1[1])/(s2[1]))
    b=s1[2]+s2[2]*(-(s1[1])/(s2[1]))
    g=b/a
    h=((s2[2]-s2[0]*g)/(s2[1])).n()
    return [g,h]
def my_det(l1,l2):
    return l1[0]*l2[1]-l2[0]*l1[1]

def func1(x,y):
    return cos(x+0.5)+y-0.8
def func2(x,y):
    return sin(y)-2*x-1.6
def dfunc1_x(x,y):
    return -sin(x+0.5)
def dfunc1_y(x,y):
    return int(1)
def dfunc2_x(x,y):
    return -2
def dfunc2_y(x,y):
    return cos(y)

eps=10^(-6)
k=0
x=-1
y=-0.5
k=0
while (1):
    k+=1
    k
    a=dfunc1_x(x,y)
    b=dfunc1_y(x,y)
    e=-func1(x,y)
    c=dfunc2_x(x,y)
    d=dfunc2_y(x,y)
    f=func2(x,y)
    l1=[a,b]
    l2=[c,d]
    l3=[-e,b]
    l4=[f,d]
    l5=[a,-e]
    l6=[c,f]
    d=my_det(l1,l2)
    d_x=my_det(l3,l4)
    d_y=my_det(l5,l6)
    g,h=(d_x)/d,(d_y)/d
    x1=x-g
    x1
    y1=y-h
    y1
    if abs(g)<eps and abs(h)<eps:
        break
    x=x1
    y=y1
x
y

plot(0.8-cos(x+0.5), (x,-2,2))+plot(arcsin(2*x+1.6),(x,-3,3))